open Dream_html
open Page_kit

(* The shell. [viewer] and [request] identify authenticated pages. Auth pages
   omit the application navigation. *)
let theme_session_key = "hito.theme"

let deployment_version () =
  match Sys.getenv_opt "HITO_VERSION" with
  | Some version when version <> "" -> version
  | _ -> "development"

let footer () =
  tag "footer"
    [ class_ "site-footer" ]
    [
      tag "div" [] [ txt "© 2026 Marius PETER. All rights reserved." ];
      tag "div" []
        [
          txt "Version: ";
          tag "code"
            [ class_ "deployment-version" ]
            [ txt "%s" (deployment_version ()) ];
        ];
    ]

let html_page ?viewer ?request ?(active = "") ?(show_nav = false)
    ?(show_footer = false) ?workout_started title content =
  let spa_client = true in
  (* The trainee is logging a workout exactly when its start epoch is present.
     The middle nav slot then shows the elapsed timer on every page, so the
     running workout is always visible; otherwise it is the routine link. *)
  let theme =
    match request with
    | Some request -> (
        match Dream.session_field request theme_session_key with
        | Some "dark" -> "dark"
        | _ -> "light")
    | None -> "light"
  in
  let nav_link page path label =
    let attrs = [ href path ] in
    let attrs =
      if spa_client then Dream_html.attr "data-hito-app-link" :: attrs
      else attrs
    in
    let attrs =
      if String.equal page active then
        Dream_html.string_attr "aria-current" "page" :: attrs
      else attrs
    in
    tag "a" attrs [ txt "%s" label ]
  in
  (* Three always-available actions. The middle slot points to the routine
     normally. While logging it becomes the elapsed workout timer. The link
     still carries the trainee to the current workout, so a running workout
     stays one tap away without adding a fourth destination. The client ticks
     the value from [data-started]. Without script the link shows a static
     start. *)
  let workout_timer_link started =
    let attrs =
      [ href Routes.workout; class_ "nav-timer" ]
      @ (if spa_client then [ Dream_html.attr "data-hito-app-link" ] else [])
      @ (if String.equal "workout" active then
           [ Dream_html.string_attr "aria-current" "page" ]
         else [])
      @ [
          Dream_html.attr "data-hito-workout-timer";
          Dream_html.string_attr "data-started" "%d" started;
          Dream_html.string_attr "role" "timer";
          Dream_html.string_attr "aria-label" "Elapsed workout time";
        ]
    in
    tag "a" attrs
      [
        tag "span"
          [
            class_ "nav-timer-value";
            Dream_html.string_attr "aria-live" "off";
            Dream_html.attr "data-hito-workout-timer-value";
          ]
          [ txt "0:00" ];
      ]
  in
  let navigation_links () =
    [
      nav_link "home" Routes.home "Home";
      (match workout_started with
      | Some started -> workout_timer_link started
      | None -> nav_link "routine" Routes.routine "Routine");
      nav_link "logbook" Routes.logbook "Logbook";
    ]
  in
  let application_navigation () =
    let visible =
      match (viewer, request) with
      | Some (_ : View_model.Viewer.t), Some _ -> true
      | _ -> show_nav
    in
    if visible then
      [
        tag "nav"
          [
            class_ "app-nav";
            Dream_html.string_attr "aria-label" "Application navigation";
          ]
          (navigation_links ());
      ]
    else []
  in
  tag "html"
    [
      Dream_html.string_attr "lang" "en";
      Dream_html.string_attr "data-theme" "%s" theme;
    ]
    [
      tag "head" []
        [
          tag "title" [] [ txt "Hito — %s" title ];
          void "meta" [ Dream_html.string_attr "charset" "utf-8" ];
          void "meta"
            [
              Dream_html.string_attr "name" "viewport";
              Dream_html.string_attr "content"
                "width=device-width,initial-scale=1";
            ];
          void "link" [ rel "stylesheet"; href Routes.stylesheet ];
          void "link"
            [
              rel "icon";
              Dream_html.string_attr "type" "image/svg+xml";
              href Routes.favicon;
            ];
        ];
      tag "body"
        [ Dream_html.string_attr "class" "hito-app" ]
        ([
           tag "a"
             [
               class_ "skip-link"; Dream_html.string_attr "href" "#main-content";
             ]
             [ txt "Skip to main content" ];
           tag "div"
             ([
                Dream_html.string_attr "class" "app-shell page-%s" active;
                Dream_html.string_attr "data-hito-page-title" "Hito — %s" title;
              ]
             @
             if spa_client then [ Dream_html.attr "data-hito-app-shell" ]
             else [])
             ([
                tag "header"
                  [ class_ "masthead" ]
                  ([
                     tag "a"
                       ([ class_ "brand"; href Routes.home ]
                       @
                       if spa_client then
                         [ Dream_html.attr "data-hito-app-link" ]
                       else [])
                       [ txt "hito" ];
                   ]
                  @ application_navigation ());
                tag "main"
                  ([ id "main-content"; tabindex "-1" ]
                  @
                  if spa_client then [ Dream_html.attr "data-hito-app-content" ]
                  else [])
                  content;
              ]
             @ if show_footer then [ footer () ] else []);
         ]
        @
        if spa_client then
          [
            tag "script"
              [ src Routes.workout_client; Dream_html.attr "defer" ]
              [];
          ]
        else []);
    ]